Question

Which type of in-vitro-in-vivo correlation compares % drug released vs % drug absorbed?

• A. Level C
• B. Level A
• C. Multiple level C
• D. Level B

Answer 1

The Correct Option is B

The question pertains to the concept of in-vitro-in-vivo correlation (IVIVC) in the field of biopharmaceutics and pharmacokinetics. IVIVC is a predictive mathematical model describing the relationship between an in vitro property of a dosage form (often drug release or dissolution) and a relevant in vivo response (often drug absorption). This is crucial for understanding how a drug will perform in the body based on laboratory tests.

There are several levels of IVIVC, each differing in the type and extent of correlation they provide. Let's examine each type:

1. Level A: This correlation is the most comprehensive and direct. It involves a point-to-point relationship between the in vitro release profile and the in vivo absorption profile. It compares the percent of drug released to the percent of drug absorbed over time. This type of correlation can predict the entire plasma drug concentration-time profile from the in vitro data. Thus, Level A IVIVC is the correct answer, as it matches the description of comparing % drug released vs % drug absorbed.
2. Level B: This correlation uses the principles of statistical moments (such as mean residence time) to create a comparison between the in vitro dissolution and the in vivo input. However, it does not provide a direct point-to-point relationship.
3. Level C: This correlation compares one dissolution parameter (like dissolution time) to one pharmacokinetic parameter (like C_max or AUC). It does not provide a full correlation over time.
4. Multiple Level C: This is an extension of Level C, where several pharmacokinetic parameters are correlated with several dissolution time points. Still, it falls short of a complete point-to-point correlation.

In conclusion, the correct answer is Level A, since it provides a direct prediction of % drug absorbed from % drug released data.